Innovative Bridge Construction:
A Success Story in Engineering
In an ambitious infrastructure project, a bridge was constructed as part of a trumpet interchange at the existing highway level, incorporating an underpass. The design featured a three-span structure with a central span of 25 meters flanked by two 20-meter spans. Post-construction, the bridge seamlessly integrated with the existing highway, with the underpass located beneath it.
Initial Design and Challenges
The original design utilized a steel H-pile foundation and post-tensioned girders seated on a cross beam to support the deck. The construction methodology planned involved excavation down to the foundation level, followed by piling. After the pipe, adding complexity and cost.
Piles were in place, the construction of the pile cap, column, and cross beam would commence. Subsequently, post-tensioned girders would be launched onto the cross beam, leading to the deck's construction
Innovative 'Top-Down' Methodology
To address these challenges, the project team adopted a ‘top-down’ construction methodology. Bore pile foundations were installed from the existing highway pavement level down to the required founding level. The cross beam was then constructed, followed by the launching of post-tensioned beams. The deck was constructed next, allowing the bridge to be opened for traffic while services were relocated to the bridge deck supports.
Once the bridge was operational, excavation for the underpass began with extreme caution to avoid disturbing or damaging the bore piles, which now served as columns. Manual excavation around the bore piles ensured precision and safety.
Successful Outcome and Savings
The innovative approach resulted in the successful completion of the bridge without relocating critical services or constructing extensive retaining structures. This not only ensured the smooth operation of the existing infrastructure but also led to significant cost savings of over BND 4 million.
This project stands as a testament to innovative engineering solutions, showcasing how challenges can be transformed into opportunities for efficiency and cost savings in large-scale infrastructure projects.
Project Details
Client:
Department of Roads, Public Works Department, Ministry of Development
Project Duration:
November 2019 – March 2022
Total Cost: BND 13 million